LinkedList C# (data structures and algorithms using C# michael mcmillan )

Question

I found This Code in a Book (data structures and algorithms using C# michael mcmillan )to do a linkedlist but i cant understand what is object after and why do we use find method and when i put it in vsc it gave me error.

(error CS1061: 'Node' does not contain a definition for 'header' and no accessible extension method 'header' accepting a first argument of type 'Node' could be found)

public class Node
{
      public Object Element;
      public Node Link;
      
      public Node()
      {
          Element = null;
          Link = null;
      }
      public Node(Object theElement)
      {
          Element = theElement;
          Link = null;
      }
}
class LinkedList
{
     protected Node header;
     public LinkedList() 
     {
         header = new Node("header");
     }

     private Node Find(Object item) 
     {
         Node current = new Node();
         current = header;
         while(current.header !=item)   //i cant understand this line page 198 in the book
              current = current.Link;
         return current;
     }
     public void Insert(Object newItem, Object after) 
     {
         Node current = new Node();
         Node newNode = new Node(newItem);
         current = Find(after);
         newNode.Link = current.Link;
         current.Link = newNode;
     }
}

Answer 1

public Node Find(Object item)
{
    Node current = new Node();
    current = header;
    while (!object.Equals(Current.Element, Item) && Current.Link !=null)
        current = current.Link;
    return current;
}